There are many places to buy pumpkin seeds, but here are a few who provide big pumpkins over 1000 pounds.
If you would like to learn more about pumpkins and the hybirds, please read the last link. They provide all sorts of hybrid seeds at commercial levels.
Giant Pumpkin Seeds
Dill’s Atlantic Giant Seeds
The world’s largest pumpkin holding many world records. Suitable for competitions or to amaze your neighbors. Trailing. 120 days.
Pumpkins Hybrids Info only “Rupps”
Additional Pumpkin Pages